Power operated doctor blade holder



Sept. 13, 1955 R. E. BEDARD POWER OPERATED DOCTOR BLADE HOLDER 2 Sheets-Sheet 1 Filed June 8, 1964 I f if! L J Jfyer Z. Be@/- Z Sept. 13, 1966 R. E. BEDARD 3,271,308

POWER OPERATED DOCTOR BLADE HOLDER Filed June 8, 1964 2 Sheets-Sheet 2 United States Patent "'ce 3,271,808 POWER OPERATED DOCTOR BLADE HOLDER Roger E. Bedard, Auburn, Mass, assignor to Lodding Engineering Corporation, Auburn, Mass, a corporation of Massachusetts Filed June 8, 1964, Ser. No. 373,377 11 Claims. (Cl. 256.5)

This invention relates to a new and improved holder for a doctor blade including power operated means for clamping the blade in position, and including means for selectively causing the blade to be pinched in operative position or to avoid the pinching so as to operative'ly mount the blade in floating relationship.

'One of the principal objects'of the invention resides in the provision of a doctor blade holder as described which is easily and quickly clamped and released under power operation and is automatically slightly opened sufliciently for the blade to be abstracted and a new blade inserted, and also including a second position for the blade holder where it is fully open for easy cleaning.

A further object of the invention resides in the provision of a power operated doctor blade holder which is closed by means of a power operated cam which can be operated to produce a very powerful clamping pressure under conditions of power operation, this actuation being substantially automatic and the doctor blade being clamped from end to end thereof by a series of devices across the entire machine simultaneously, thus avoiding the necessity of an operator moving across the machine and operating several different clamps one after the other, the power operation of the present case providing for uniform clamping pressure as well as simultaneous clamping action the entire length of the doctor blade.

A further object of the invention resides in the provision of a power operated doctor blade clamping apparatus as above described which is made in several independent sections across the machine, each of which is provided with its own individual power device, all of which however are operated simultaneously from a single position at the side of the machine, both for the clamping action and the partial opening action for the replacement of the blades.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings in which:

FIG. 1 is a plan view illustrating the construction of the new doctor blade clamp;

FIG. 2 is a sectional view on line 2-2 of FIG. 1;

FIG. 3 is a sectional view on line 33 of FIG. 1 illustrating a detail of construction, and

FIG. 4 is a view in rear elevation, looking in the direction of arrow 4 in FIG. 1.

In illustrating the invention there is shown a conventional doctor blade 10 which is adapted to scrape or doctor a roll having a surface not shown but as is well known in the art. There is a support 12 for the doctor blade, this support extending across the entire machine and in turn being mounted on a tilting support 14, the details of which are not shown as the same is well known in the art. The support 14 mounts thereon a series of bearings 16 only one of which is shown herein, but it is to be understood that there are a series of these mounted on the support 14 and extending across the machine to provide for a series of devices which are now to be described for clamping the blade continuously across the machine.

'On each bearing 16 there is provided an extension generally indicated at 18, this extension mounting the support 12 and also mounting a pivot 20 for a clamp arm 22. The pivot 20 is generally parallel with respect to the supports 12 and 16 and also to the blade, and it provides for 3,271,808 Patented Sept. 13, 1966 rotational motion of the arm 22 as for instance from the dotted line position in FIG. 2 to the solid line position in FIGS. 1 and 2. The solid line position thereof shows the same in clamping condition whereas the dotted line position shows the clamp fully open for cleaning the apparatus.

The clamping arm 22 has a free end portion at 24 on which is mounted the actual clamp means 26 as by means of a pair of fasteners 28 or the like, and it will be seen that the clamp member 26 extends parallel with support '12, etc., transversely well past the side edge portions of the arm 22 which lies in an accommodating groove 30 in the member 18. At the rearward edge of the clamping member 26 as shown in FIG. 2, there is an opening or recess 32 which is provided with a slanted wall 34, this wall being on an incline with respect to the support 12 and also with respect to the clamping surface of member 26 as clearly shown in FIG. 2.

Also mounted on the bearing 16 in any way desired is an air cylinder 36. Although the connections for this air cylinder are not shown, it is to be understood that it is provided as usual with air source, valve, etc., which go to operate in a reciprocating manner a ram or piston rod 38. To this piston rod there is secured in any desired manner a wedge rod 40 having a surface at 42 which is complementary to the'inclined surface 34. When the wedge rod 49 is moved to the left in FIG. 2 under influence of the air cylinder, it will be seen that it moves the member 26 down to the member 12, clamping the blade 10 and pinching it in the area which is indicated at 44 by reason of the fact that the clamping surface of the support 12 is relieved somewhat.

The connection between rod 38 and rod 40 may be of any desired means. When the parts are set in the relationship desired, they can be pinned by any desired means such as a cotter-pin 46 which is shown in FIG. 2, for retraction. Also if desired the wedge rod 40 can be. most simply made in cylindrical form and it can be provided with a longitudinal groove at 48 receiving a screw 50 which prevents it from turning as it moves in and out between the dotted and solid line positions thereof as indicated in FIG. 2. Also if desired a slide bearing of any desired type as at 52 can be utilized to support the wedge rod.

The support 12 has a'continuous raised rear edge portion 54 which extends across the machine and the wedge rod 40 extends through an opening in this member in which the slide bearing 52 is located. As seen in FIG. 1 the recess 32 can be made longer than necessary in order to accommodate the parts. Also mounted at the top rear edge of the clamping member 26 there is a spring member 56. This spring member extends as shown in FIG. 3 to the rear and has a downturned lip 58 which rest-s on the top edge of the extending member 54 when the clamping member is not quite in the clamping relationship which is shown in FIG. 2. When the air cylinders are operated to more closely clamp the member 26 i.e., moving it downwardly, tension is placed on the spring 58 so that it moves to the dotted line position in FIG. 3. Thus when the air cylinders are returned to unclamping position, the spring 56 will cause the clamping member 26 to release the blade automatically so that it can be easily abstracted and a new blade inserted. On the other hand however if it is desired to clean the clamp, then the operator merely manually moves the clamp from the solid line position of FIG. 2 to the dotted line position thereof, thus completely opening up the entire device.

Also when it is desired not to pinch the blade, i.e., it is desired to leave the blade in floating relationship, a selflocking adjustment screw 60 can be utilized. This screw 60 is easily turned from the top of the arm 22 to project it more or less downwardly. When it is turned to move downwardly so that it engages the bottom of the slot 30 as at 62, then it will be clear that the clamp 26 is not able to move down to the FIG. 2 position but is stopped short thereof a very small amount so that the blade is then free, but of course held in operative position nevertheless in what is known as a floating position.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but What I claim is:

1. A doctor blade holder for a doctor blade comprising an elongated bar, means supporting the bar, .a supporting surface on the bar against which the doctor blade is to be clamped, a member to cooperate with said supporting surface for clamping the doctor blade between the member and the surface, said member being movable to and from said clamping surface, means for moving the member from a blade-release position to a blade-clamping position, said means including a fluid-operated cylinder, a rod actuated thereby, cooperating cam means between the rod and the member operative to urge the member to bladeholding position upon motion of the rod under influence of the fluid-operated'cylinder, said rod having a retracted, inoperative position completely free of the member.

2. The doctor blade holder recited in claim 1 wherein said blade clamping member is pivotable, and when the rod is retracted, has a range of pivotal motion greater than merely necessary to free the blade for full opening of the holder.

3. The doctor blade holder recited in claim 1 wherein said blade-clamping member has an extra range of motion when free of the rod for completely opening the holder.

4. The doctor blade holder recited in claim 1 including means automatically separating the member from the blade-clamping surface upon release of the member from the rod.

5. The doctor blade holder recite-d in claim 1 including means automatically separating the member from the blade-clamping surface upon release of the member from the rod, said last-named means including a resilient element.

*6. The doctor blade holder recited in claim 1 including limit means for engaging said blade-clamping member and preventing it from moving into blade-pinching position under influence of said rod, said last-named means being adjustable.

7. The doctor blade holder recited in claim 1 including limit means for engaging said blade-clamping member and preventing it from moving into blade-pinching position under influence of said rod, said last-named means being adjustable between ranges Where it is completely inoperative to provide for blade-pinching, or adjustable to provide a stop at different distances between the bladeclamping member and said surface, said limit means being located directly between the member and the bar.

8. A doctor blade holder for a doctor blade comprising an elongated bar having a supporting surface for the doctor blade, a pivotab-le blade-clamping member arranged on an .aXis to move between a blade released condition and a blade-clamping position opposite said supporting surface, a fluidoperated cylinder, a free ended rod for said cylinder, cooperating wedge-type cam means on said member and said rod whereby said member may be forced into tight clamping engagement with the blade against said supporting surface, upon motion of said rod in a predetermined direction, said blade-clamping member being completely free of said rod when m? latter is moved by said cylinder in the opposite direction, said blade-clamping member then being relatively freely movable beyond blade released condition to completely open the doctor blade holder.

9. The doctor blade recited in claim 8 including adjustable limiting means limiting the degree of approach of said blade-clamping member with respect to said supporting surface in order to avoid pinching the blade, said means being selectively adjustable to a position where it is inoperative, said limit means being located directly between the member and the bar.

10. The doctor blade holder recited in claim 8 including means for maintaining rectilinear non-rotational motion of said rod into and out of engagement with said Wedge-type cam means on said blade-holding member.

11. The doctor blade holder recited in claim 8 including resilient means bearing on the blade-clamping member to tend to move it to blade released position.

References Cited by the Examiner UNITED STATES PATENTS 2,850,926 9/1958 Jobe 269-229 X 3,078,825 2/1963 M-unton et al 15-2565 X 3,119,331 1/1964 Koch et al 26925 X FOREIGN PATENTS 649,468 1/ 1951 Great Britain.

CHARLES A. WILLMUTH, Primary Examiner.

L. G. MACHLIN, Assistant Examiner. 

1. A DOCTOR BLADE HOLDER FOR A DOCTOR BLADE COMPRISING AN ELONGATED BAR, MEANS SUPPORTING THE BAR, A SUPPORTING SURFACE ON THE BAR AGAINST WHICH THE DOCTOR BLADE IS TO BE CLAMPED, A MEMBER TO COOPERATE WITH SAID SUPPORTING SURFACE FOR CLAMPING THE DOCTOR BLADE BETWEEN THE MEMBER AND THE SURFACE, SAID MEMBER BEING MOVABLE TO AND FROM SAID CLAMPING SURFACE, MEANS FOR MOVING THE MEMBER FROM A BLADE-RELEASE POSITION TO A BLADE-CLAMPING POSITION, SAID MEANS INCLUDING A FLUID-OPERATED CYLINDER, A ROD ACTUATED THEREBY, COOPERATING CAM MEANS BETWEEN THE ROD 